Impact of Ambient O3 on Physiological, Visual, and Growth Responses of Sensitive Eastern Hardwood Tree Species Under Natural and Varying Site ConditionsEPA Grant Number: R825244
Title: Impact of Ambient O3 on Physiological, Visual, and Growth Responses of Sensitive Eastern Hardwood Tree Species Under Natural and Varying Site Conditions
Investigators: Skelly, John , Davis, Donald D. , Ferdinand, Jon , Savage, James E. , Schaub, Marcus , Steiner, Kim C. , Stevenson, Richard E. , Zhang, Jianwei
Current Investigators: Skelly, John , Davis, Donald D. , Steiner, Kim C.
Institution: Pennsylvania State University
EPA Project Officer: Chung, Serena
Project Period: November 1, 1996 through October 31, 1999 (Extended to October 31, 2001)
Project Amount: $494,000
RFA: Air Quality (1996) RFA Text | Recipients Lists
Research Category: Air , Air Quality and Air Toxics
The objectives of this project include: 1) the determination of ozone exposure/response relationships to the ontogeny of visible foliar injury symptoms on sensitive eastern hardwood tree species under ambient ozone exposures and under natural forest conditions; 2) the determination of the interrelationships between microsite factors and leaf physiological responses leading to differences in foliar symptom expressions using forest and open-top chamber exposures; 3) determining pre-visual changes in Rubisco as an indicator of pre-visual physiological manifestations, symptoms, early leaf senescence, and growth patterns; and 4) determining whether radial growth or the relationship between ring width variation and climate differ in relation to foliar symptom severity within and among natural populations of three ozone sensitive hardwood tree species. The studies will be conducted within the Shenandoah National Park, Virginia, where previous studies have identified significant differences in ozone induced foliar injuries to three sensitive hardwood species with elevation and microsite conditions (soil moisture, aspect, etc.) apparently playing significant roles in the development of symptoms under the respective ambient ozone exposures. Exposure/response measures will be interpreted in light of several ozone exposure parameters of significance to the new ozone National Ambient Air Quality Standards.